In producing semiconductor components and flat panel displays, various processes such as etching, coating, cleaning or carrying of a substrate are repetitively performed while horizontally holding the rear surface of a substrate such as a semiconductor wafer or a liquid crystal substrate by a substrate holding unit.
Since the rear surface of the substrate contacts the substrate holding unit when various processes are performed, convex portions may be formed at the rear surface of the substrate.
While the rear surface of the substrate having the convex portions is cleaned by a scrubber adopting a brush, it is difficult to satisfactorily remove the convex portions and planarize the rear surface of the substrate.
Therefore, a method may be conceived which planarizes the rear surface of the substrate by polishing the entire rear surface of the substrate uniformly using, for example, an apparatus disclosed in Japanese Patent Application Laid-Open No. H08-71511.